US2779510A - Vibrational dispenser for forming solid gas mixtures - Google Patents

Description

Jan, 29, 1957 J. L. WILSON ETAL 2,779,510

VIBRATIONAL DISPENSER FOR FQRMING SOLID GAS MIXTURES Filed Sept. 27, 1954 Carrier Gas INVENTORS JACK L. WILSON ALBERT M. GONAS ATTORNEY United States Patent 2,719,510 VIBRATIONAL DISPENSER FOR FORMING SOLID GAS MIXTURES Jack L. Wilson and Albert M. Gonas, Niagara Falls, N. Y., assignors to Union Carbide and Carbon Corporation, a corporation of New York Application September 27, 1954, Serial No. 458,325

12 Claims. (Cl. 222-193) This invention relates to improved apparatus for delivering powdered or otherwise finely divided solid material to a carrier gas stream by vibrational means at a predetermined and uniform rate.

In various metallurgical processes, it is necessary that powdered, or otherwise finely divided, solid material be conveyed to a reaction zone by a carrier gas. For example, in a recently-developed process of shielded inert gas metal arc welding, wherein the welding zone is shielded by an inert gas, such as helium, argon and the like, a welding composition is introduced with thdshielding gas stream by a powder dispensing apparatus and carried into the arc zone and fused with the weld metal to obtain beneficial shielding and fluxing results. The introduction of this finely divided solid material into the carrier gas stream is, however, in many instances, unevenly proportioned so that over a given period, more material is fed at one moment than another, thus destroying the uniformity with which the welding Zone is fluxed. This non-uniform distribution of powdered material may, at times, clog up carrier tubes to an extent that it-is necessary to discontinue operations until such tubes are cleaned or replaced.

Heretofore, dispensing apparatus of this type consisted primarily of a conveying element associated at one end with a material hopper and at the other end with an exit conduit. The flow of material along the conveying element was attained by actuating with a magnetic vibrator or similar means. The rate of powder flow from the dis pensing apparatus was controlled by such means as varying the slip angle of the powdered material or by adjusting the frequency of vibration impressed upon the conveying element. The slip angle of the powdered material was varied by changing the inclination of this conveying element in a vertical plane with respect to the horizontal, or by altering the vibration axis orientation.

The powdered material in such prior apparatus followed a path down through the hopper to the conveying element and was carried by vibrational means to the exit,

conduit. The fiow of material from the hopper was generally accomplished by either of two means; vibration of the material hopper simultaneously with the conveying element or solely by gravitational means. The former means, having the hopper rigidly attached to the conveying element, introduced variations in amplitude of vibration dependent upon the amount of material in the hopper; the latter means often resulted in clogging in the absence of a vibrating source, thereby preventing an evenly distributed flow of powdered material.

As an alternate means for vibration, a separate vibrating source was attached to the material hopper to prevent the clogging action introduced by gravitational flow alone, or by the flow of coarse materials, but this necessitated a separate vibration-governing device in addition to that controlling the, vibration of the conveying element.

It is, therefore, an object of the present invention to provide apparatus for simultaneously forming a mixture Of gas and a powdered, or, otherwise finely divided," solid improved means for controlling the material flow from. the hopper to the conveying element of the dispensing v apparatus to assure a more uniformly distributed flow, with a smaller percentage of error in feeding rates than heretofore obtained.

It is a further object of the present invention to provide means associated with the hopper and conveying element of the apparatus whereby a major amount of the vibrational energy impressed upon the conveying element is absorbed and only a component of this vibrational energy is transmitted to the hopper to assist the material flow, thereby eliminating the need for a separate vibrating source associated with the material hopper, and the need for altering the degree of vibration of the hopper as the:

amount of material within the hopper changes.

It is a still further object of the present invention to provide means for visually inspecting the amount of material being conveyed through the dispenser, thereby insuring against the ever-present possibility of clogging and breakdown.

In accordance with the present invention, a gas-tight material dispenser is provided which depends upon a vibrating action to conveyjthe solid material to the carrier gas stream. In order to more fully describe the apparatus of the invention, reference is made to the single figure of the drawing which schematically shows apparatus embodying the invention.

Closed material hopper 10 is provided for holding the powdered, or otherwise finely divided, solid material, for example, a granulated welding composition, and sealing cap 12 is employed to make hopper 1t) pressure-tight. Transfer chamber 14, having first end 16 and second end 18, conveys the powder material, deposited at first end 16 to outlet conduit means 20 associated with second end,-

18 of transfer chamber 14.

Main gas inlet means 22 is provided to direct the flow of carrier gas, which may be any gas inert to the solid material, such as argon, helium, carbon monoxide, car- 24 is employed to introduce a portion of the gas into hopper 10 in order to equalize the pressure within the hopper member with other gas-tight internal portions of the dispenser to insure the vibrational-gravitational flow of material into the transfer chamber 14 and to prevent against back up and clogging of the material within the hopper 10 due to back pressure within the hopper member.

Delivery conduit means 30, communicating gas-tightly between hopper 10 and first end 16 of transfer chamber 14, is provided for supplying the powdered material from hopper 10 to transfer chamber 14. An important feature of delivery conduit means 30- is powder flow control pipe:

means 32, "extending into transfer chamber 14 to an adjustable height above 1fioor34 of transfer chamber 14, Vertical spacing 36 between powder flow control pipe; means'32 and floor 34 of transfer chamber 14 is pro-' vided to control the flow of the powdered material from hopper 10 by varying the height of powder flow control pipe means 32.

Asan alternate means for adustment of' the. .height. of powder flow control pipe. means '32" and vertical spacing.

3'6, slide housing 42' can be raised or lowered to; the.

desired height on the. vertical stand'rod 4'4. and'held. in.

position-by set screws 46. Either of'these or similar proceduresgmaybeemployed for adjusting vertical spacing 36' to controlthe flow of powdered material from hopper 10. to transfer chamber 14.

Delivery conduit means 301s also provided'witlivibration, -dampener-'coupling 48, which may. be composed of.

rubber: or a similar resilient material whichwill attenuate the amplitude; of vibrations transmitted to hopper It). The vibrationalamplitude'impressed upon transfer chamber 14 and, powder flow control pipe means 32' is to a great extent absorbed by vibrational dampener coupling,

48; However, a component amplitude, which will vary as thequantityof the contents within the hopper changes, is allowed'to pass into hopper 10. This eliminates the need for' aseparate vibrating source attached to material hopper 1 =-and=assures a uniformly distributed flow, freer from clogging. S'incethematerial hopper is vibrated by only: a component of; the amplitude impressed upon the transfer chamber 14, it is notsubject' to a varying degree of vibration;

Transfer chamber 14is' secured to magnetic. vibrator. 50'through clamp means 52, and platform 54. Theimv pressed-i vibration of the instrument, at controlled. fre: quencies, carries the powdered material, deposited by delivery conduit means 30 at first end 16 of transfer chamber--14, acrossfloor'34 of transfer chamber 14 to second end IS-Where mixing with the carrier gas. stream occurs to produce a solid-gas mixture, which is passed.

from thedispenser. through outlet conduit means20.

It" lias been found preferable to construct. transfer chamber 14'of transparent material, thereby enablinga continuous visual inspection of the amount of material beingconveyed. through the dispenser to: the carrier gas stream; The possibility of carrying a greater. or. lesser than desired quantity of'material'through the tubesis always;present'due to possible faulty adjustment .of apparatus=andthe like- Since this mightcause clogging. of. the.

exit" tubes andnecessitate' a complete stoppage of. opera.- tions, visual inspection is very desirable.

Amaterial dispenser. embodying the invention .was employed in a welding application to dispense a, crushed welding. composition approximately 20 x200 mesh. The welding composition was, fed. from the hopped. through they exit conduit means 20 atsa,considerablenumber of closelycontro-lledrateswithin the range of from approximately 0.5 to .250 grams per minute. Forthe minimum fiowrate, verticali spacing 36.. between powder flow con: trol pipe means. 32' and floor. 34. of transfen chamber 14 was as little as V of an inch. Theerror. infeeding rates was carefully measured and found. to vary, from .lessythan approximately 2% at 30 grams. per minute to less than 115% at 250 grams per minute. The evennessof. flow of the carrier gas-powdered"materialtmixture,contribur ted greatly tofthe quality of the resultantweld. Atno timewasthe operation stoppedv dueto. clogging of, the lead. pipes. It {has been found preferable that, the. pewderedmaterial; when .used as. a weldingtcomposition, be.

of-mesh size no larger than 8llx D.

Powder dispensers. constructediin. accordance .with the present invention. have. been; found. to operatesuccessfully with. many different powdered, or; otherwise finely,

tia. gable within less than 2% error; and are simple in construction, dependable in operation, and economical to construct and maintain.

What is claimed is:

l. A vibrational gas-tight powder dispenser for forming solid-gas mixtures comprising, in combination, a closed material hopper;;a closed'transfer. chamber having first and second ends; delivery conduit means communieating, gas-tightly between said hopper and said first end of. said transfer. chamber for supplyingpowd'ered material from said hopper to said transfer chamber, said delivery conduit means containing powder flow control pipe means extending into said transfer chamber to a regulated height above the floor. of saidtransfer chamber, whereby the rate of flow of said powdered material to said transfer chamber is controlled; first gas inlet means associated with said second end of said transfer chamber. for supplying gas to there form said solid-gas mixture; second gasinlet'means associated with said hopper for supplying. gas to maintain a pressuretherein sufficient to equalize the pressure withinsaid transfer chamber for preventing back up and clogging of said powdered-material within said hopper; means for vibrating said transfer. chamber so as to passpowdered material along said floor ofsaid transfer chamber from said first end to said second end;. and outletconduit means associated'with said second end of said transfer chamber for conveying said solid-gas mixture from said dispenser.

2; A vibrational.gas-tightpowderdispenser for forming solid-gas mixtures in accordance with claim l,.also comprisingmeans" for. adjusting saidpowder flow control pipe means toa variable height above said fioor'ofsaid' transfer chamber, whereby the flow of saidpowdered'material'to'said transfer chamber is controlled.

3'. A vibrational gas tight'powderidispenser for forming solid-gas mixtures comprising. in combination; a. closed material hopper; a'closed' transfer chamber having'first andsecond ends; deliveryconduitmeans' communicating gas'tightly betweensaid hopper and said'first end of said transfer chamber for supplying powdered material from said hopper to said transfer chamber, said delivery conduit means containing vibration dampener coupling means communicating gas-tightly between said hopperand' said powder flow control pipe means for dampening vibrations of said transfer chamber transmitted'to said hopper, whereby only a component of said vibration is transmitted to said-hopper for'conducing the flow of said powdered material to said transfer chainber; first gas inlet meansassociated with said secondend' of said" transfer chamber for supplying gas to there'form" said solid-gas mixture; second gas inlet means associ= ated with said hopper for supplying gas to maintain a pressure thereinsufficient to equalize the pressure within said transfer, chamber forpreventing' backup" and cloggingzofsaid'powderedrmaterial within said hopper; means for vibrating said transfer chamber so as to pass" saidpowdered material'along'said'floor ofsaid transfer chain ber fromsaidifirst end' to saidsecond end; and outlet conduitmeans associatedwith said secondend of said transfer: chamber for conveyingsaid solid-gas mixture from" saiddispenser.

4.v A: v-ibrational gas-tight powder dispenser for forming: solidigas mixtures comprising, in combination, a closedimaterial hopper; aclosed' transfer" chamber hav-'- ing first: and 5 second" ends; delivery conduit means com municating gas-tightly between said hopper and 'saidfirst end of .saidttransfer chamber forsupplyingpowdered materia'lrfrom said'fh'opper to said transfer chamber; first gas. iinletzmeansa associated i with said second end of 'said 1 transferrchamberifora supplying" gasto there formsaid. solid-gas. mixturmt-second gas: inlet meansi assoeiatedf witli said hopper for 'supplyingagas tomainta-in'a' pressureith'ere in sufficient to equalize the pressure within said transfer" chamber; for. preventing". back zupand clogging; of" said powdered materialiwithin said'shopperg means for vibrav ing";saidttransferrchamber so' as topass said powdered ma terial along said floor of said transfer chamber from said first end to said second end; and outlet conduit means as-;

sociated with said second end of said transfer chamber for conveying said solid-gas mixture from said dispenser; said transfer chamber being constructed of transparent material to permit visual inspection of the rate of feed of said powdered material passing through said transfer chamber to said gas.

5. A vibrational gas-tight powder dispenser for forming solid-gas mixtures comprising, in combination, a closed material hopper; a closed transfer chamber having first and second ends; delivery conduit means communicating gas-tightly between said hopper and said first end of said transfer chamber for supplying powdered material from said hopper to said transfer chamber, said delivery conduit means containing powder flow control pipe means extending into said transfer chamber to a regulated height above the floor of said transfer chamber, whereby the rate of flow of said powdered material to said transfer chamber is controlled; first gas inlet means associated with said second end of said transfer chamber for supplying gas to there form said solid-gas mixture; second gas inlet means associated with said hopper for supplying gas to maintain a pressure therein suflicient to equalize the pressure within said transfer chamber for preventing back up and clogging of said powdered material within said hopper; means for vibrating said transfer chamber so as to pass said powdered material along said floor of said transfer chamber from said first end to said second end; and outlet conduit means associated with said second end of said transfer chamber for conveying said solid-gas mixture from said dispenser; said transfer chamber being constructed of transparent material to permit visual inspection of the rate of feed of said powdered material passing through said transfer chamber to said gas.

6. A vibrational gas-tight powder dispenser for forming solid-gas mixtures in accordance with claim 5, also comprising means for adjusting said powder flow control pipe means to a variable height above said floor of said transfer chamber, whereby the flow of said powdered material to said transfer chamber is controlled.

7. A vibrational gas-tight powder dispenser for forming solid-gas mixtures comprising, in combination, a closed material hopper; a closed transfer chamber having first and second ends; delivery conduit means communicating gas-tightly between said hopper and said first end of said transfer chamber for supplying powdered material from said hopper to said transfer chamber, said delivery conduit means containing powder flow control pipe means extending into said transfer chamber to a regulated height above the floor of said transfer chamber, whereby the rate of flow of said powdered material to said transfer chamber is controlled, said delivery conduit means containing vibration dampener coupling means communicating gas-tightly between said hopper and said powder flow control pipe means for dampening vibration of said transfer chamber transmitted to said hopper, whereby only a component of said vibration is transmitted to said hopper for conducing the flow of said powdered material to said transfer chamber; first gas inlet means associated with said second end of said transfer chamber for supplying gas to there form said solid-gas mixture; second gas inlet means associated with said hopper for supplying gas to maintain a pressure therein sufficient to equalize the pressure within said transfer chamber for preventing back up and clogging of said powdered material within said hopper; means for vibrating said transfer chamber so as to pass said powdered material along said floor of said transfer chamber from said first end to said second end; and outlet conduit means associated with said second end of said transfer chamber for conveying said solid-gas mixture from said dispenser.

8. A vibrational gas-tight powder dispenser for forming solid-gas mixtures in accordance with claim 7, also comprising means for adjusting said powder. flow control,

pipe meansto a variable height above said floorof said transfer chamber, whereby the flow of saidpowdered material to said transfer chamber is controlled, r

9. A vibrational gas-tight powder dispenser for forming solid-gas mixtures comprising, in combination, a closed material hopper; a closed transfer chamber having first and second ends; delivery conduit means communicating gas-tightly between said hopper and said first end of said transfer chamber for supplying powdered material from said hopper to said transfer. chamber, said delivery conduit means containing vibration dampener coupling means communicating gas-tightly between said hopper and said powder flow control pipe means for dampening vibrations of said transfer chamber transmitted to said hopper, whereby only a component of said vibration is transmitted to said hopper for con-,

ducing the flow of said powdered material to said transfer chamber; first gas inlet means associated with said second end of said transfer chamber for supplying gas t there form said solid-gas mixture; second gas inlet means associated with said hopper for supplying gas to maintain a pressure therein sufiicient to equalize the pressure within said transfer chamber for preventing back up and clogging of said powdered material within said hopper; means for vibrating said transfer chamber so as to pass said powdered material along said floor of said transfer chamber from said first end to said second end; and outlet conduit means associated with said second end of said transfer chamber for conveying said solid-gas mixture from said dispenser; said transfer chamber being constructed of transparent material to permit visual inspection of the rate of feed of said powdered material passing through said transfer chamber to said gas.

10. A vibrational gas-tight powder dispenser for forming solid-gas mixtures comprising, in combiantion, a closed material hopper; a closed transfer chamber having first and second ends; delivery conduit means communieating gas-tightly between said hopper and said first end of said transfer chamber for supplying powdered material from said hopper to said transfer chamber, said delivery conduit means containing powder flow control pipe means extending into said transfer chamber to a regulated height above the floor of said transfer chamber, whereby the rate of flow of said powdered material to said transfer chamber is controlled, said delivery conduit means containing vibration dampener coupling means communicating gas-tightly between said hopper and said powder flow control pipe means for dampening vibration of said transfer chamber transmitted to said hopper, whereby only a component of said vibration is transmitted to said hopper for conducing the flow of said powdered material to said transfer chamber; first gas inlet means associated with saidsecond end of said transfer chamber for supplying gas to there form said solid-gas mixture; second gas inlet means associated with said hopper for supplying gas to maintain a pressure therein sufficient to equalize the pressure within said transfer chamber'for preventing back up and clogging of said powdered material within said hopper; means for vibrating said transfer chamber so as to pass said powdered material along said floor of said transfer chamber from said first end to said second end; and outlet conduit means associated with said second end of said transfer chamber for conveying said solid-gas mixture from said dispenser; said transfer chamber being constructed of transparent material to permit visual inspection of the rate of feed of said powdered material passing through said transfer chamber to said gas.

11. A vibrational gas-tight powder dispenser for forming solid-gas mixtures comprising, in combination, a closed material hopper; a closed transfer chamber having first and second ends; delivery conduit means communicating gas-tightlybetween said hopper and said first end of said transfer chamber for supplying powdered material from said hopper to said transfer chamber, said delivery -cnnduit:' n'rearrs containing powder-how control pipe: means extending. into" said transfer chamberto a regulat'd height above*the'fiborofsaid tr'ansfer chamber,

whereby the-'ratenf flew of said powdered material t6- said transfer-chamber"iseontrolledg first gas inlet means associated-with said second end' of said transfer chamber forsupplying' gas to 'there formsaidsolid-gas mixture; second gas inlet means associated with said hopperfbr supplying gas-t0 maintain a -pressure therein sufficient to equalize the-pressure within said transfer chamber fb'r preventing back up and clogging of" saidpowderedmaterial within said hopper; main gas inlet means associated with said first gas inlet means a'nd said s'econd gas inlet means for" supplying tlieretb' gas underpressure; means for" vibrating said transfer 'clieunber."'s'0--as'to pass" s'aitI powdere'd -materialalong said floor of seiii' transfer chain-- her from said? first end t0s'aii1 second end}, and outlet ecinduit 'mean's associated' 'with" said sec'ond' end' of said transfer chamber for "conveying s'aiid solid-gas mixture fron'i's'aid dispenser.

1-2. vibrational gas-tightpowder dispenser fol fornv in'g selid gas mixturesin accordance with claim 11, also c'o mpri'singmea'fls for adjusting sa'idpOWder flow control p'ip'e means to variable height above said floor of said transfer chamber, whereby the flow of said powdered material to said transfer chamber is controlled.

Referene'es' Cited in the file ofthis pat'ent UNITED STATES PATENTS 1,323,633 Weber Dec'. 2, 1919- 2,077,898 ROHT' we h. -Apr.120, 1937 2,187,117 Weya'ndt Jan. 23; 1940 2 ,568,332 Genovese .s -.1 "Sept. 18, 195 1-

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